This invention relates to a separable electrical connector having an improved arrangement for retaining an insert within a shell.
An electrical connector of the type herein includes a dielectric insert which is retained in a metallic shell and carries a plurality of conductive terminals in electrical isolation from the shell for mating with a respective plurality of terminals in a second connector. The dielectric insert typically is hard and can either be comprised of a thermoset or a thermoplastic material with good dielectric properties for circuit isolation.
Previous approaches for retaining an insert assembly within the shell have included upset staking of the shell, metal ring staking, and copper mesh/epoxy laminate staking. Each of these offer excellent retention but may introduce a conductive path between the insert assembly and shell. In "Electrical Connector" U.S. Pat. No. 4,019,799 and "Method of Making Electrical Connector" U.S. Pat. No. 4,099,233 issuing to Bouvier, respectively, Apr. 26, 1977 and July 11, 1978, and each incorporated herein by reference, it has been found that deforming the conductive mesh laminate by a crushing action caused the mesh to invade into the bond interface between a hard wafer and a resilient grommet whereupon a conductive path could be established between the outer row of terminals and the shell thereby causing a ground short to exist.
Other approaches have included epoxy staking, interference fits with epoxy, and self-snapping mechanisms, all of which protect against a conductive path to the shell but do not offer a good insert retention system. Epoxy does not have an internal reinforcement to prevent break up under extreme conditions of temperature and pressure. Further, the interference fits with epoxy rely on the epoxy to take up sloppy fits due to tolerancing. Slippage and loose friction fits could lead to insert pull-out. Self snapping mechanisms introduce loose inserts due to tolerancing difficulties.
Another approach has utilized a non-metallic laminate mesh. This offers good retention and assures a non-conductive path between the insert and shell but is hard to handle and process.
Provision of a non-conductive insert retention system that would be inexpensive, adaptable to a wide range of connector shells having different diameters and internal cross-sections, easy to manufacture, easy to assemble, and assure the user of insert retention integrity would be desirable.